Heat Tape Wiring Instructions by Paul Sage

I have tried both soldering heat tape and using the connectors. Using the connectors takes up more space because of the extra parts, and I have had difficulty making contact with the tape. I decided to use the soldering method for the shelving unit I recently built. Below are some basic instructions for hard-wiring heat tape.

You will need:

heat tape foil tape (optional)

masking tape electrical tape

solder wire nuts

an extension or repair cord a straight-edge razor blade

sharp scissors soldering iron

wire cutter/stripper

First, determine how long of a section of heat tape you need. Keep in mind that you’ll need a little space at one end for the connections. I do not recommend bending or folding heat tape, as it can get too hot when it makes contact with itself. When you’ve determined how long of a piece you need, make sure that you cut it with a very sharp scissors. You can cut it straight across, even though the elements in the tape run diagonally. ***(Please note that I have attached a strip of foil tape along the backside of the heat tape. This is not required, but it does help to direct the heat upwards instead of down into the shelf.)

To begin making the connections to the heat tape, I prefer to attach the section to a board with masking tape. This keeps the heat tape from moving around or rolling up while you are trying to solder it. Position the tape with the ‘metal’ side up. You will need to remove the plastic coating from both of the metal strips at the end where you plan to make your connections. Some people just use the soldering iron to melt it away, but I prefer to use a single-edge razor blade to scrape the plastic off. You should only need to scrape the plastic off of a ¾ to 1 inch section of heat tape.

Once you have the plastic coating removed from the points where you will be making contact with your line cord, you can position the cord using more masking tape. You should strip the insulation off of each end of the cord in a length equal to that of where you scraped the plastic off the heat tape. Make sure that the exposed sections of the cord are directly over the exposed sections of heat tape.

When you have the ends of the line cord in place, you can begin soldering them to the heat tape. This process can take a while, so don’t rush it. If the plastic part of the heat tape gets too hot, it can start to warp or catch fire. Begin by using a little solder dripped off the end of the soldering iron to attach the cord to the heat tape. Then begin to add more solder along the length of the exposed cord. Be sure that the solder is bonding to the metal strip in the heat tape as well as covering the cord. After the solder has cooled, you can then cover all exposed metal with electrical tape. The electrical tape should cover all of the solder, the end of the line cord, and the edge of the heat tape. You will also need to affix a strip of electrical tape over the opposite end of the heat tape. Because the heat tape was cut, the metal strips are slightly exposed. These ends could make contact with something conductive (like your arm) and give off a shock or short out.

After you have covered all of the exposed metal with electrical tape, you can cut the line cord to the desired length. In this picture, I have five four-foot sections of heat tape already assembled and ready for installation. At this point, I use an extension cord with the female end cut off to test each section of heat tape. I simply use two wire nuts to connect each section to the extension cord, and then I plug it in. If you don’t feel it start to warm up within 10-15 seconds, chances are that one or both of the soldered connections did not make contact, and need to be redone. Once you feel the heat tape start to warm up, unplug it immediately! If it’s curled or folded upon itself, it can start to overheat very quickly.

Now, depending upon the application, this is where your project may be a bit different from how I explain things here. The main difference is that I used the foil tape on top of the heat tape as well. I chose to do it this way to hold the heat tape in place and protect it. Also, the heat tape is only 3” wide, but by covering it with two sections of the foil tape, it ended up approximately 5” wide. The metal in the tape transfers heat all the way to the edges. This provides a wider heated area.

Next position the pre-assembled section of heat tape where you want it in your rack or shelf. I prefer to use a few small pieces of double-sided tape to hold it in place. In my example, the back of the shelving unit is made out of ¼” thick pegboard. The line cord easily feeds through one of the holes, but you may need to drill or router out a channel for your line cord. The end of the heat tape, as well as the line cord, should be held in place very firmly. This will prevent it from being damaged and potentially breaking the soldered contacts.

Once the heat tape is positioned where you want it, you can cover it with the foil tape if you choose to do so. Working with the foil tape can be a little tricky. You want to avoid having any creases or folds in it, as your tubs or tanks will catch it as you slide them in and out. I prefer to start with a piece of foil tape that is about 2-3” longer than the heat tape. This will help hold the connected end in place. (In the picture, I forgot to do this, and had to go back with a smaller piece of tape to cover up the end) I separate the backing from the heat tape at just one end, and then slowly peel it out from underneath the foil tape as I press and smooth it out. Working with a 4’ piece of foil tape that has had the entire backing removed is NOT fun and I don’t recommend it. The foil tape sticks a lot better to a clean and smooth surface. The shelves in the picture are actually made of aspen, and I applied two coats of polyurethane, lightly sanded, and then applied two more coats. This left the wood with a very smooth surface that the tape stuck to well. The tape will also stick to melamine, but I advise removing all dust and residues prior to attaching the tape. The tape will NOT stick to bare wood for very long, if at all.

This is how the connected end of the tape should look. Notice how the end of the heat tape is completely covered, and the cords are neatly tucked out a hole in the back. This will prevent you from accidentally catching it and breaking a connection.

This picture shows what one section of heat tape should look like when it has been installed. There are no bubbles or wrinkles in the foil tape for the tanks to catch on, and the entire section of tape is firmly held in place.

Now comes the easy part. When all sections of heat tape are installed, you can begin “piggy-backing” their line cords. For this project I started from the top, since the thermostat is mounted underneath the bottom shelf. I prefer to hold the cords in place by using wire staples or cable holders. This will also help to prevent the cord getting pulled on from the back, which would jeopardize the soldered connections. When making these connections, be sure to use the appropriate size wire nuts. You will probably need to cut the line cords to an appropriate length so that there isn’t loose cord hanging out the back or bottom. Note: You will need to strip approximately ½” of the insulation off of each wire that you join. Although you can use a knife to do this, it’s much easier to use a wire-stripping tool like the one pictured on page 1. Twist the bare ends of the cords together in a clockwise direction. This will ensure the best connection and avoid breaking the wires since the wire nuts are screwed on in a clockwise direction as well. The cord from the top shelf (A) can drop right down to where the cord from the next shelf (B) comes out. You will need to join these two pairs of cords with a third pair (Z) that will drop down to the next shelf down. Note that this third pair (Z) is a separate piece of cord, not a cord from one of the heat tape sections. The third pair of cords (Z) will drop to where the line cord comes out from the next shelf down (C). These two pair of cords will then join with a third pair (Y), and so on. Assuming that shelf C is the last section of heat tape, the cord that you connect to it (Y) should be the cord you will plug into a thermostat. I use an extension cord with the female end cut off, just like the one mentioned earlier to test each section of heat tape. *You will need to use a thermostat for the heat tape for proper temperature regulation. For this unit, I chose to use a Ranco brand thermostat (purchased from Matt Graybeal).

DISCLAIMER: I cannot accept any responsibility for damage caused by the misuse of any heating or electrical equipment. This article is merely a pictorial guide for how I installed heat tape into a shelving unit. Installation of such components should only be attempted by a qualified individual.

Copyrighted Material

Do not duplicate without written permission © 2005 Paul Sage Reptiles